US2630066A - Incendiary bomb - Google Patents

Description

March 3, 1953 s. e. PONDERI ETAL INCENDIARY BOMB Filed Feb. 8, 1945 grWfl/YM SPEERS G. PONDER HARRY M. BRANDT Patented Mar. 3, 1953 ITED;

[E GFFIZCE 2 Claims:

(GrantednnderTitle 35,.

7 sec. 1

'Ihe'invention describ ed hereimmayzb ezmanm f-aetn-red 'and' used by Or -forytliefiovernmentiior governmental purposes withoutr the :payment; to us of any royaltythereonzu This invention relates particularly. ?tc1 :ras tail v. ejeetidn -ty pebomb i designed "to have 'azhigh: termin-a1 velocitysuitable: for: precision bombing from high altitudes andiforipenetrationfinto resisting structures. It relatestmore:particularly totail ejectiombombs-havingan eificient'capacity fordiicendiary-fillings; 1

Since the begnming of 'the' present" war; much efiort has 'beemdvoted todevelopin'g' tail ejection bombs intended 'to' function after penetrating a target to forcefuliy eject a largemasswf; incendiary =material5 To fu'lfill its-functions efsweetly; the bomb should have a: high: filling capacity; a high drop I accuracy and reliable -ej ection 'action; Certaintail'ejection' type incendiary bombs meeting these requirements'havebeen designed but have had th'e disadvantage :of zzbeing unsuitable for pin point bombingland unsuitable for" penetrating resisting roof 'structuresuof lindiistrial and storage installations Tl i'e present inventionhas the "object :of' providing a bomb having-ballistics:comparablexto 21 250 1b? *general 'purpose .bom'b eveniwithfa much relatively smallersize unit', e. g. 30".to 45 1'bS'."lfavorable- 'for clustering andnlmeetingzrequirements set forth;

The-"tail ej ecti'onctype bomhiprovidedfllherewith functions efiiciently' -wi-tli theaid 50f the following-features: 14w;:arbodyrwithlalstreamlined'form yet withhigh fillingtcapaciti ylh) xasnose haying piercing ability with anoidancetoi crnshing"and disruption; of; the :bcmbis filing-mechanism; ;:and (c) an extensible tau": fora;flightistabilizationlde signed to accommodate the: bcmbcfdr; efficient cliistering 'in a re'stricted spaca- Int additionato these several features' other :cooperating'features V fermed fifr stz ueture piercing action ami adapted; r

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for holding zansiantispersonnel; explosive: charge iwith part-of the:firing:mechanism-, an adapter member 5 of heavy: construction":fonattaching the nose member. 3 :to ath'e: bodycasing-rand for holding t other parts: .of i a J fuze" .:mechanism i'antl sealing members; and a tail structure 6 -.to;which is attached an extensible tail-assembly:

The nose :member is; advantageously: given-1a thick i'walbconstruction andf an :ogival -r form :for

" improvement 'ofi strength; flight. and piercing action; In 1133013611"TEEIZTBIICLZthE nose member has" a threaded portion 1' 'for :engagementrwith a threaded fiangeiofxthe ad'aptorrii: Two zsmail depressions 8 "in: the nose member 3 areausedrfor I insertion of wrench/prongs for screwingrtheznose memberiinto the-adaptor 5. An aperture 9. 10 cated at the'central' lowerrextremitypfnnse member 3 isfprovided for receiving a"firing:ipin plunger head I 0;. which: is retainedziiniitsioutermost position by the 'shouldenll adjoining the aperture '9.

A closedcup-shaped member: l2 having acentral tubular inside wall l3 closely fits theiinside Wall of nose member 3 andis useful Jessa-container of a high'rexplosive :charge 4,; also" as a containerv for a time delay fuse .l 4;" The explosive charge 4 may comprise any '"suitable high explosive substance such asptetryl, TNT, orfthe'like, capable of -fragmentingsnose:member's fend sending the fragments at "high velocity' into" space.

' The time 1 delay "fuse may beza. corditypefuse containing aislow burningiblack. powder composition', such. as alconventi'onalfMiners fuser' V The time delay. fuseis preferably disposed as'aicompact Windingat thecnnoper:partxotthe container I 2 :with aitpartition; l separating ;the :fusei-from the explosive charge 4, but withta'final burning end: 16 projected: throughta' small hole for: contact :with .the explosive: charge 74;

The. head I ll "of 'ithe'ffiring pin plunger is attached to firing pin l I which extends through the' 'passagedefined'by the" tubular closure l3. A coil spring l8 surrounding-the firingpin-l'! is under compressionbetweenhead'1!0 an'dthebase ..of adaptor Evfortmaintaining.the' firing pinrin an outwardly projected'apositio'n:until it isforced to' yieldfcni impact Ofilthfi ibQmbEWithathe fuze armed;

The adaptor'fi has-a-xlateral bore 1 9"for receiving a slidable safety pin plungerxZO; which'when depressed inwardly by-pressureof 'an 'ad acent bomb in acluster unarmsethe 'fuze'in obstructing movement: of the :firing :pin: If! toward a; primer 2 I". l A coil spring?! surronnding'thecsaityypin 2!! undercompresslon tendsiito ieiect the esafie'ty p to the thicker Wall casing --tion is fastened'and secured to casing I to be 3 pin 20 when relieved of pressure on its external head end.

The primer cap 2| is seated in a suitable part of the adaptor plate 5 aligned with the firing pin I! for ignition thereby. Contiguous to the primer cap 2| is placed a suitable delay powder train 23, such as may contain slow burning composition for obtaining a time delay burning of about 1 to 3 seconds before a first fire charge 24 of black powder is affected. The first fire charge is preferably contained by a plastic cup 25 cemented to the end of the delay train and primer cap holder 26 for separation from an ejection charge 21.

The ejection charge 21 comprises a suitable amount of a propellent powder such as grade A#4 Army glazed black powder for obtaining the desired ejection of the bomb filling. It is preferred that the ejection charge contain an admixture of finely divided pyrophoric material, such as pow- 'dered magnesium coated with about 3% linseed oil, or aluminum powder. A suitable ejection charge comprises at least about 4 to '7 g. of the black powder with about equal amount of the powdered magnesium coated with about 3% of the linseed oil.

the side .of the adaptor 5 affords a convenient means for filling the cavity between dome 25 and the dome 29 with a white phosphorus charge. The threaded opening 36 may be closed after the filling with a suitable threaded plug (not shown). The casing forming the principal part of the bomb body is advantageously formed of pressed sheet-metal having satisfactory structural strength with thinness to increase the filling capacity, e. g., sheet steel of about 19 gage. For

improved ballistics, the casing i may be designed to give the bomb a more streamlined shape by widening its cross section near the middle part.

' For more efficient clustering the casing I may be polygonal in cross section rather than circular.

At its tail end of the bomb, the casing I is preferably extended into a tapered thinner wall section 6. The section 6 may be an integral part of casing Or be sheet metal of thinner wall brazed The thin wall secsusceptible to disruption therefrom upon ejection of the incendiary charge 2 when the ejection charge 21 is fired.

At its apex, the conical or pyramidal tail end section 6 is secured to a sealing plug 3| in threaded engagement with adaptor 32. A tubular Well 33 is sealed at its upper end to a bottom circular projection 34 of adaptor 32 and extends centrally down into the bomb to a closed bottom 35. A slidable tubular plunger 3'! is flared outwardly at its end which slides along the inner surface of well 33 and is projected outwardly from the well by the force of the compressed coil spring 38. The coil spring 38 has ends bearing against the bottom closure 35 of the well and extends through the tubular plunger 31 to its upper closure 39. A

' threaded sleeve 40 engaged with the adaptor 32 surrounds the plunger 31 and acts as a stop to prevent complete ejection of the plunger when the flared bottom end of the plunger is blocked in its movement by the bottom of sleeve 40.

A set of pressed steel vanes 4| are afiixed to the upper extremity of the plunger 31 and contoured on their inner edges to permit the nesting of the bomb in the vanes when the plunger is depressed by pressure of another body in the cluster. Upon release of the bomb from a cluster, the plunger is forced outwardly by the action of the coil spring 38 so that flight stabilizing of the vanes is most effective.

For use as an incendiary, the filling 2 may have various compositions. A suitable type of incendiary oil filling is formulated by gelling gasoline or naphthahydrocarbon liquids with soaps that form stabilized gels, such as, mixtures of aluminum soaps of saturated and unsaturated fatty acids, e. g., stearates and oleates, and also such soaps with the mixtures of naphthenates and palmitates. The gelling soaps are generally used in proportions of about 7 to 15% by weight of the liquid fuel. Other suitable incendiary fillings may be formulated from liquid hydrocarbon fuels with mixtures of gelling or thickening agents, such as isobutyl methacrylate polymer, rubber, and oil thickening resins or synthetic elastomers. The gelled or thickened materials may contain dispersed finely divided complete solid materials, such as, pyrophoric materials like finely divided magnesium, cellulose nitrate, powdered carbon, Woodmeal, and the like.

The bomb falling with true flight is in a substantially vertical position on striking a target, so that the force of impact is received on the head ||l of the firing pin. The fuze having been armed by ejection of the safety pin 20 when the bomb was released from a cluster dropped from aircraft, the firing pin I! is driven by the impact into primer 2!, igniting the delay train 23, which in time ignites the first fire charge 24. The ejection charge 21 is fired by the first fire charge 24 and it explosively lifts the ceiling domes 2 8 and 29 and forces the white phosphorus filling 30 and the incendiary filling 2 toward the tail of the bomb. The tail section 6 together with its attached stabilizing assembly is blown off and the incendiary charge is ejected from the rear of the bomb by the fired ejection charge.

In the bore 42 through the adaptor plate 5, the ejection charge 21, upon being ignited, flashes back to initiate burning of the time delay fuse I4, which after one or several seconds, depending upon the length and type of the fuse, detonates the anti-personnel charge. The fuse l4 may be timed to effect explosion of the anti-personnel fragmentation charge following ejection of the incendiary filling. The heavy anti-personnel charge deters fire fighting and allows the incendiary opportunity to act.

It has been determined that a bomb of the type described and illustrated, is useful for precision bombing of selected targets and has a much better penetrating effectiveness than other known types of incendiary bombs.

Although the invention has been described in detail with reference to one embodiment, it is to be understood that other modifications come within the spirit and scope of the invention.

We claim:

1. An incendiary bomb having a unitary nose structure comprising a hollow cap with a forward end, a base secured to said cap forming at least in part a compartment adapted to contain an explosive in the forward end of the cap and adjacent one side of the base, a primer mounted in the base, a firing pin mounted in the nose and extending through said cap so that one end of the pin is adjacent the primer and the other end is adjacent the forward end of the cap, the arrangement being such that the firing pin detonates the primer upon impact of the forward end of the cap with an object, a fluid-tight container comprising spaced substantially cup-shaped metallic sheets secured to the opposite side of the base, said sheets forming a container for a kindling charge in the space therebetween and forming at least in part a chamber having an ejection charge adjacent said opposite side of the base, a container positioned in the chamber and having a starting charge therein, a fuse communicating with the container and the primer, another fuse having one end thereof in communication with the chamber andthe other end in communication with the compartment, a hollow body portion having an incendiary substance therein, means for securing the base to the body portion so that the fluid-tight container is positioned adjacent said body portion, and a tail piece on the opposite end of said body member and mounted thereon sothat pressure within said body member caused by setting ofi of the incendiary material by the kindling material will cause the tail piece to be released from the body.

2. A bomb having a nose structure adapted to contain an anti-personnel bursting charge, a hol-v low body portion secured to said nose structure and adapted to contain an incendiary charge and a tail structure secured to said body portion away from said nose structure adapted to stabilize said bomb during flight and be separated from said body portion upon ejection of said incendiary charge, said nose structure comprising a hollow cap with a forward end, a base secured to said cap forming at least in part a compartment adapted to contain an anti-personnel explosive in the forward end of said cap, a firing pin mounted in said cap extending therethrough adapted for axial movement toward said base, a primer mounted in said base adjacent said pin to flash rearwardly through said base away from said compartment upon impact with said pin, a frangible container adapted to contain a starting charge se- 6 cured to said base behind said primer, a first fuse in said base between said primer and said container adapted to control the time of ignition of said starting charge after ignition of said primer, a first frangible cup positioned adjacent said base on the rearward side thereof spaced apart from said container defining with said base and said container a chamber adapted to hold an ejection charge, a second frangible cup adjacent said base on the rearward side thereof concentrically surrounding said first frangible cup but spaced apart therefrom to define a kindling charge container and a second fuse extending through said base connecting said ejection charge container with said cap compartment, adapted to control the time of explosion of said nose charge after explosion of said ejection charge, whereby upon impact of said firing pin with an object, said primer, first fuse starting and ejection charges coact to separate said tail portion and eject said kindling and incendiary charges rearwardly out of said body portion, and said second fuse coacts to detonate thereafter said anti-personnel explosive in said cap.

SPEERS G. PONDER.

HARRY M. BRANDT.

REFERENCES CITED The following references are of record in the

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